A Solution
An enduring feature of "science" reporting during the 1930s was atomic energy. Scientists had raised the possibility from the time of the discovery of radioactive decay among the natural elements in 1902. The measurement of the masses of hydrogen and helium to unusual precision in 1922 by Francis Aston of the Cavendish Laboratory in Cambridge, England, gave perhaps the first substantial ground for hope or fear that civilization might run or destroy itself by exploiting the atom. Aston found that four atoms of hydrogen have a greater mass than one of helium; should it be possible to synthesize helium from hydrogen, Einstein's law of equivalency between mass and energy promised that something noteworthy would ensue. According to his calculations, Aston said, the hydrogen in a pint of water could yield enough energy to drive a steamship across the ocean and back; or "the transmutation might be beyond control and result in the detonation of all the water on the earth," a possibility he considered "interesting" but remote. If all went well, "there would be literally no limit to the material achievements of the human race."[107]
Most reputable physicists, Max Planck for example, wrote of the need, desirability, and eventual practicality of "the liberation
of atomic energy."[108] Scientists who thought practical atomic energy farfetched or impossible found it awkward to protest, since they would open themselves to the difficult duty of proving an impossibility. Millikan was one of the few physicists who then talked regularly with the Creator and could know the impossibility of the release of useful or destructive atomic energy. One of the favorite arguments of those who favored a moratorium in physical research turned on the likelihood that unsupervised physicists might discover a way and unprepared society might blow itself to bits. No chance, said Millikan. His observations of cosmic rays, which showed that the sort of synthesis Aston contemplated could not occur on earth, and his calculations about radioactive decay, which showed that atomic disintegration could not power a popcorn machine, demonstrated sufficiently that God had made the universe proof against destruction by inquisitive physicists. "There is not even a remote likelihood that man can ever tap this source of energy at all."[109]
Millikan was gainsaid by the Compton brothers: by Arthur, who discredited Caltech's conception of cosmic rays, and by Karl, who, in January 1933, predicted the arrival of useful atomic energy—or, at least, of "the most exciting and far-reaching developments in the whole history of science"—within a generation.[110] The venue for this utterance could not have been more public or more appropriate: the Century of Progress Exposition, whose centerpiece was a huge robot, signifying science, pushing a man and a woman into the future. The high-tech razzle-dazzle of the exposition incorporated a "philosophy of showmanship for the contributions of science and their applications" developed by a committee headed by Frank Jewett in cooperation with the NRC. No mundane signal like the radio call that activated the Diesel at the San Francisco fair would do for Chicago: the Century of
Progress Exposition came to life at the command of forty-year-old light from the star Arcturus collected at several observatories and forwarded by Western Union. As F.K. Richtmeyer, dean of the Graduate School of Cornell, said in celebration, "Scientific research pays large dividends." Would the study of the atom do so? When? "There is no telling," according to the dean, "when a scientific Columbus is going to discover another America."[111]
Compton's prediction and others even less responsible excited what Lawrence called a "newspaper ballyhoo." That was too much for the great proprietor of the nucleus, Lord Rutherford, who thundered before the British Association in the fall of 1933 that "anyone who says that with the means at present at our disposal and with our present knowledge we can utilize atomic energy is talking moonshine." The thunder made the front page of the New York Herald Tribune , with some echoes by American physicists. The editors of Scientific American applauded Rutherford's statement, although, they said, it was hardly scientific to rule out the possibility. Against them stood Lawrence, who by then was shooting at nuclei with projectiles from his cyclotron. To him, according to the Tribune , release of useful energy is "purely a matter of marksmanship."[112] This view of the matter appears to have attracted the attention of Einstein. At a conference arranged by the new National Association of Science Writers, he disparaged the efficacy of Lawrence's artillery. "'You see,' he said, with his characteristic sense of humor and picturesque expression, 'it is like shooting birds in the dark in a country where there are only a few birds.'"[113]
Against the public declarations of Rutherford and Einstein, and within an environment not favorable to an economic transformation of the sort that atomic power was expected to bring ("It appears doubtful . . . whether coal mining or oil production could survive after a couple of years"),[114] Lawrence thought it prudent
to blunt his many hints that nuclear physicists might open the atom for business. In the early 1930s these hints came primarily in direct connection with victualling his laboratory. In a memorandum of accomplishments written in 1933, for example, he pointed to data indicating the release of energy in disintegration, and hinted, "This is a matter of great scientific interest and eventually may have a practical application." In asking for the renewal of a student's fellowship, he wrote that the experiments it supported "have the possibility of contributing knowledge which may ultimately lead to utilization of [the] vast store of atomic energy." Nor did he disdain to make the same point when requesting the loan of a pound of beryllium from an industrial supplier: "If a means can be found for stimulating on a large scale the explosion of beryllium nuclei, a practically unlimited store of energy is thereby made available."[115]
By the mid 1930s Lawrence was in great demand as a speaker. He often took the opportunity to hint at practical atomic energy. The "University Explorer," a radio show originating at the University of California and carried by the networks, asked him in 1936 what the future might hold. "I'm almost afraid to guess," he replied. "Speaking officially, as one scientist, I can only say that we are going to continue our studies." And unofficially? "Certainly we are much closer to [the release of subatomic energy] than we were a few years ago. . . . If we can discover a method of starting chain reactions . . . the problem would be solved." Again, speaking officially, at commencement exercises at the Stevens Institute of Technology in 1937: "It is only of interest [here, at this engineering school, where speculation has no place] to indicate the present state of knowledge with proper humility." Current knowledge made the release of atomic energy appear "fantastic;" no one had any idea how to do it and the second law of thermodynamics might forbid it. And yet, unofficially: "It is conceivable that in our lifetime this great principle [the transformation of mass into energy] will play a vital role in technical developments which at
the moment are beyond our dreams—for such has been the history of science."[116]
By this time, 1937, the nucleus had become the enduring fad of physics. A marginal topic before the crash, it was absorbing 10 percent of the efforts of physical scientists, as reported in Science Abstracts , during the depths of the Depression. The increase of interest and labor, as expressed by the content of the the Physical Review , was so sharp that even the numbers that represent it are dramatic: in 1932, 8 percent of its articles, letters, and abstracts concerned nuclear physics; in 1933, 18 percent; in 1937, 32 percent.[117] Men beginning their careers in physics in the early 1930s saw the nucleus as (to quote one of them) an unstudied frontier, a research land of opportunity, a gold field. The young Otto Robert Frisch, a Viennese who had studied all over Europe, wrote of the nucleus—the unerforschtes Neuland , the Goldfelder —like a Forty-niner.[118] The metaphor was most apt. Although several of the key discoveries that excited interest in the nucleus during the Depression were not made in the United States, the Americans, with their big machines and high pressure, very quickly dominated the field. And the field dominated them. A physicist inexpert in nuclear physics in 1937 was, according to one of them, Arnold Sommerfeld, who had taught atomic theory to all of Europe, "completely uneducated by American standards."[119]
At the head of the American expeditionary force against the nuclear citadel stood Ernest Lawrence. He was the quintessential American leader, active, youthful, optimistic. He had built while others idled, sustained while others retrenched, inspired while others doubted. "The trade of a 'cyclotroneer,'" wrote one of his students in an unintended double entendre, "is one which has experienced no depression."[120]
Was the cyclotron "a product of the land of the Golden Gate"? The question was put to Donald Cooksey, then Lawrence's alter ego, by a reporter at the Golden Gate International Exposition of 1939. Cooksey was standing in the exposition's Hall of Science, before a full-scale model of the latest cyclotron. The model used steel balls accelerated by gravity to knock apart a representation of a lithium atom, "which is unable to defend itself against such vigorous attack, and is blown to bits." But is it Californian? "It literally and truly is," Cooksey replied. "Practically coincident with the opening of this marvelous Exposition [on San Francisco Bay] is the culmination of years of development [at Berkeley] of the world's largest cyclotron." Attempting to reduce its capacity to his audience's, Cooksey estimated that it would shoot more "atomic bullets" in one second than all the real bullets that all the machine guns in the world could fire off during the entire life of the exposition. "Or more than one gun could fire in three million years."[121] How this machine and its predecessors came to be created in California, how their sizes and uses grew, how they and their makers spread throughout the land, and how the machines and the men went off to war, are the main subjects of this book.